The Bitterroot is holding in a relatively stable late-October pattern, but the approaching weather system could change things before the weekend. Recent measurements have the lower river near Missoula in the low 800s cfs, down from the bigger flows earlier in October. The river remains clear and technical, with trout generally using deeper seams, riffle transitions, foam lines, and slower holding water.

The biggest story this week is the forecast. Wednesday should bring mild temperatures and good conditions for anglers hoping to get out before the storm. Thursday brings increasing clouds and showers, followed by much colder weather and rain Friday. Higher elevations could pick up additional snow.

The colder weather should continue to keep water temperatures in an excellent range for trout, although chilly mornings may slow feeding activity. Late morning through mid-afternoon will likely remain the most productive window. If precipitation increases flows slightly without muddying the river, fishing could improve.

Fall Hatches

The fall hatch program is becoming more important than ever. BWOs should be a primary focus, particularly when Thursday's clouds and Friday's rain arrive. These conditions can encourage longer hatching windows and bring selective trout to the surface.

Mahogany Duns are still worth having available, especially in sizes 14–16. Hecubas remain another fall mayfly to watch for, although their activity is becoming less dependable as the season progresses.

Anglers are already seeing October Caddis, and larger orange-bodied dries may still produce in broken riffles and along banks. October Caddis pupa can also be effective under an indicator or larger dry.

Terrestrials are fading quickly, but an occasional beetle, ant, or small hopper can still interest trout during warmer afternoons. Smaller terrestrials will generally be more believable than large foam patterns at this point in the season.

Nymphing should remain consistent before the hatch activity begins. Fish Frenchies, Perdigons, Pheasant Tails, and BWO nymphs through deeper seams and soft buckets. Watch carefully for fish rising in slower tailouts before switching to dries.

Streamer fishing could be especially productive during this weather change. The combination of cooler temperatures, clouds, and possibly higher water creates an opportunity to move larger trout. Fish olive or black sculpins, Thin Mints, Sparkle Minnows, and smaller articulated patterns along banks and deeper structure.

Outlook for the Weekend

Thursday and Friday could provide the best BWO and streamer conditions if water clarity holds. Saturday should be cooler and more settled, with fishing likely improving after the cold morning hours.

What's Working

Dry Flies

• BWO Parachutes #18–22

• BWO Comparaduns #18–22

• Mahogany Duns #14–16

• Hecubas #10–12

• October Caddis Adults #8–12

• Purple Haze #16–20

• Parachute Adams #16–20

• Griffith's Gnats #18–22

• Beetles #12–16

• Ants #14–18

Nymphs

• Frenchies #14–18

• Perdigons #16–20

• Pheasant Tails #16–20

• BWO Nymphs #18–22

• October Caddis Pupa #8–12

• Duracells #14–18

• Zebra Midges #18–22

• Jigged Hare's Ears #14–18

Streamers

• Sparkle Minnows

• Thin Mints

• Mini Dungeons

• Sculpzilla

• Woolly Buggers

• Olive and Black Sculpins